Methods and mechanisms for balloon launching

ABSTRACT

A method for balloon launching may include loading a pre-packaged balloon and payload into a shell structure. The pre-packaged balloon may be pulled out of its packaging in a vertical direction, for instance using a gantry crane. The gantry crane may be configured to inflate the balloon from the top of the envelope. The balloon may be inflated while substantially within the shell structure, which may provide protection from wind gusts. A vehicle, such as a heavy forklift, may provide mobility and support for the balloon and shell. Optionally, once the balloon is inflated, the vehicle may move the balloon/shell combination at a rate and direction substantially matching the current wind direction/speed. Furthermore, after reaching a zero-velocity condition relative to the wind, the vehicle may assist and/or initiate the opening of the shell. A tether connecting the balloon to the shell structure may be disconnected, allowing the balloon to launch.

BACKGROUND

Unless otherwise indicated herein, the materials described in thissection are not prior art to the claims in this application and are notadmitted to be prior art by inclusion in this section.

Computing devices such as personal computers, laptop computers, tabletcomputers, cellular phones, and countless types of Internet-capabledevices are increasingly prevalent in numerous aspects of modern life.As such, the demand for data connectivity via the Internet, cellulardata networks, and other such networks, is growing. However, there aremany areas of the world where data connectivity is still unavailable, orif available, is unreliable and/or costly. Accordingly, additionalnetwork infrastructure is desirable.

Network infrastructure may be costly, however, and thus, some techniquesmay utilize temporary or non-permanent structures. Deployment of suchtemporary or non-permanent structures may also present challenges.

SUMMARY

In a first aspect, a method is provided. The method includes providing aballoon positioned substantially within a shell structure. The balloonincludes an envelope in an initially packed state. The envelope in theinitially packed state includes the envelope being uninflated andcompressed. The method further includes while the balloon issubstantially within the shell structure, unpacking the envelope in adirection substantially perpendicular to a ground surface so as tostretch the envelope. The method additionally includes while the balloonis substantially within the shell structure, filling the envelope with alift gas. The method may optionally include determining, based on winddata associated with an external environment outside the shellstructure, a wind direction and a wind velocity of wind in the externalenvironment. Yet further, the method optionally includes causing theshell structure to move in a direction and at a velocity resulting in asubstantial zero-wind condition. The zero-wind condition includes thedirection being in about the wind direction and the velocity being atabout the wind velocity. The method may also optionally include inresponse to the substantial zero-wind condition, causing the shellstructure to open such that the balloon is exposed to the externalenvironment, and launching the balloon.

In a second aspect, a system is provided. The system includes a shellstructure configured to substantially enclose a balloon and open suchthat the balloon is exposed to an external environment. The balloonincludes an envelope in an initially packed state. The envelope in theinitially packed state includes the envelope being uninflated andcompressed. The external environment includes environmental conditionsoutside the shell structure. The system further includes a lift elementconfigured to lift the envelope and fill the envelope. Unpacking theenvelope includes stretching the envelope in a direction substantiallyperpendicular to a ground surface. Filling the envelope includes fillingthe envelope with a lift gas. The system may optionally include amovement element configured to move the shell structure in a planesubstantially parallel to the ground surface. The system additionallyincludes a control system configured to, while the shell structureencloses the balloon, cause the lift element to unpack the envelope. Thecontrol system may be further configured to, while the shell structureencloses the balloon, cause the lift element to fill the envelope. Thecontrol system may be optionally configured to determine, based on winddata from at least one wind sensor, a wind direction and a wind velocityof wind in the external environment. The control system may also beoptionally configured to cause the movement element to move in adirection and at a velocity resulting in a substantial zero-windcondition. The zero-wind condition includes the direction being in aboutthe wind direction and the velocity being at about the wind velocity.The control system may also be optionally configured to, in response tothe substantial zero-wind condition, cause the shell structure to openand the balloon to launch.

In a third aspect, a non-transitory computer readable medium havingstored instructions is provided. The instructions are executable by acomputing device to cause the computing device to perform functions. Thefunctions include causing an envelope of a balloon to be unpacked in adirection substantially perpendicular to a ground surface so as tostretch the envelope. The balloon includes the envelope in an initiallypacked state. The envelope in the initially packed state includes theenvelope being uninflated. A shell structure encloses the balloon. Thefunctions further include causing the envelope to be filled with gas.

In a fourth aspect, another system is provided that includes a means forproviding a balloon positioned substantially within a shell structure.The balloon includes an envelope in an initially packed state. Theenvelope in the initially packed state includes the envelope beinguninflated and compressed. The system further includes, while theballoon is substantially within the shell structure, a means forunpacking the envelope in a direction substantially perpendicular to aground surface so as to stretch the envelope. The system additionallyincludes while the balloon is substantially within the shell structure,a means for filling the envelope with a lift gas. The system mayoptionally include a means for determining, based on wind dataassociated with an external environment outside the shell structure, awind direction and a wind velocity of wind in the external environment,and a means for causing the shell structure to move in a direction andat a velocity resulting in a substantial zero-wind condition. Thezero-wind condition includes the direction being in about the winddirection and the velocity being at about the wind velocity. The systemmay optionally include, in response to the substantial zero-windcondition, a means for causing the shell structure to open such that theballoon is exposed to the external environment, and launching theballoon.

These as well as other aspects, advantages, and alternatives, willbecome apparent to those of ordinary skill in the art by reading thefollowing detailed description, with reference where appropriate to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram illustrating a balloon network,according to an example embodiment.

FIG. 2 is a simplified block diagram illustrating a balloon-networkcontrol system, according to an example embodiment.

FIG. 3 is a simplified block diagram illustrating a high-altitudeballoon, according to an example embodiment.

FIG. 4 is a simplified block diagram illustrating a balloon-launchingsystem, according to an example embodiment.

FIG. 5 depicts a balloon-loading scenario, according to an exampleembodiment.

FIG. 6 depicts a balloon-unpacking scenario, according to an exampleembodiment.

FIG. 7 depicts a balloon-inflation scenario, according to an exampleembodiment.

FIG. 8 depicts an optional balloon-launching scenario, according to anexample embodiment.

FIG. 9 is a method, according to an example embodiment.

FIG. 10 is a method, according to an example embodiment.

DETAILED DESCRIPTION

Example methods and systems are described herein. Any example embodimentor feature described herein is not necessarily to be construed aspreferred or advantageous over other embodiments or features. Theexample embodiments described herein are not meant to be limiting. Itwill be readily understood that certain aspects of the disclosed systemsand methods can be arranged and combined in a wide variety of differentconfigurations, all of which are contemplated herein.

Furthermore, the particular arrangements shown in the Figures should notbe viewed as limiting. It should be understood that other embodimentsmay include more or less of each element shown in a given Figure.Further, some of the illustrated elements may be combined or omitted.Yet further, an example embodiment may include elements that are notillustrated in the Figures.

1. Overview

Example embodiments help to provide a data network that includes aplurality of balloons; for example, a mesh network formed byhigh-altitude balloons deployed in the stratosphere. Since winds in thestratosphere may affect the locations of the balloons in a differentialmanner, each balloon in an example network may be configured to changeits horizontal position by adjusting its vertical position (i.e.,altitude). For instance, by adjusting its altitude, a balloon may beable find winds that will carry it horizontally (e.g., latitudinallyand/or longitudinally) to a desired horizontal location.

Further, in an example balloon network, the balloons may communicatewith one another using free-space optical communications. For instance,the balloons may be configured for optical communications usingultra-bright LEDs (which are also referred to as “high-power” or“high-output” LEDs). In some instances, lasers could be used instead ofor in addition to LEDs, although regulations for laser communicationsmay restrict laser usage. In addition, the balloons may communicate withground-based station(s) using radio-frequency (RF) communications.

In some embodiments, a high-altitude-balloon network may be homogenous.That is, the balloons in a high-altitude-balloon network could besubstantially similar to each other in one or more ways. Morespecifically, in a homogenous high-altitude-balloon network, eachballoon is configured to communicate with one or more other balloons viafree-space optical links. Further, some or all of the balloons in such anetwork, may additionally be configured to communicate with ground-basedand/or satellite-based station(s) using RF and/or opticalcommunications. Thus, in some embodiments, the balloons may behomogenous in so far as each balloon is configured for free-spaceoptical communication with other balloons, but heterogeneous with regardto RF communications with ground-based stations.

In other embodiments, a high-altitude-balloon network may beheterogeneous, and thus may include two or more different types ofballoons. For example, some balloons in a heterogeneous network may beconfigured as super-nodes, while other balloons may be configured assub-nodes. It is also possible that some balloons in a heterogeneousnetwork may be configured to function as both a super-node and asub-node. Such balloons may function as either a super-node or asub-node at a particular time, or, alternatively, act as bothsimultaneously depending on the context. For instance, an exampleballoon could aggregate search requests of a first type to transmit to aground-based station. The example balloon could also send searchrequests of a second type to another balloon, which could act as asuper-node in that context. Further, some balloons, which may besuper-nodes in an example embodiment, can be configured to communicatevia optical links with ground-based stations and/or satellites.

In an example configuration, the super-node balloons may be configuredto communicate with nearby super-node balloons via free-space opticallinks. However, the sub-node balloons may not be configured forfree-space optical communication, and may instead be configured for someother type of communication, such as RF communications. In that case, asuper-node may be further configured to communicate with sub-nodes usingRF communications. Thus, the sub-nodes may relay communications betweenthe super-nodes and one or more ground-based stations using RFcommunications. In this way, the super-nodes may collectively functionas backhaul for the balloon network, while the sub-nodes function torelay communications from the super-nodes to ground-based stations.

The present disclosure describes various example embodiments ofapparatuses, methods, and functions executable by a computer-readablemedium that are generally operable to aid in the launching of balloonsthat may operate in such a high-altitude balloon network. Beneficially,the disclosed methods and mechanisms may improve the operationallifespan of balloon envelopes, which may reduce the maintenance and/orcosts involved with operating the balloon network. Namely, the disclosedmethods and mechanisms may provide protection from wind gusts duringballoon inflation and/or launch.

In an example embodiment, a method may include providing a balloonpositioned substantially within a shell structure. The balloon mayinclude an envelope in an initially packed state. The envelope in theinitially packed state could include the envelope being uninflated andcompressed. For example, the envelope could be initially packed within aprotective package or shipping container.

The method may also include, while the balloon is substantially withinthe shell structure, unpacking the envelope in a direction substantiallyperpendicular to a ground surface so as to stretch the envelope. Inother words, the envelope could be stretched, for instance by a liftelement or lift winch, in a vertical direction.

Further, the method may include, while the balloon is substantiallywithin the shell structure, filling the envelope with a lift gas. Forexample, the lift gas could be introduced to the envelope via a fillhose coupled to the lift element or lift winch.

Additionally, the method may include determining, based on wind dataassociated with an external environment outside the shell structure, awind direction and a wind velocity of wind in the external environment.

Yet further, the method may include causing the shell structure to movein a direction and at a velocity resulting in a substantial zero-windcondition. The zero-wind condition may include the direction being inabout the wind direction and the velocity being at about the windvelocity. For example, the shell structure and the balloon could bemoved in an effort to match the wind direction and wind velocity. Insome embodiments, a forklift or other vehicle could move the shellstructure.

The method may also include, in response to the substantial zero-windcondition, causing the shell structure to open such that the balloon isexposed to the external environment, and launching the balloon. Forexample, upon determining that the shell structure is moving atapproximately the same velocity and direction as the wind in theexternal environment, the shell structure may be opened and the balloonmay be launched.

2. Example Balloon Networks

FIG. 1 is a simplified block diagram illustrating a balloon network 100,according to an example embodiment. As shown, balloon network 100includes balloons 102A to 102F, which are configured to communicate withone another via free-space optical links 104. Balloons 102A to 102Fcould additionally or alternatively be configured to communicate withone another via RF links 114. Balloons 102A to 102F may collectivelyfunction as a mesh network for packet-data communications. Further, atleast some of balloons 102A and 102B may be configured for RFcommunications with ground-based stations 106 and 112 via respective RFlinks 108. Further, some balloons, such as balloon 102F, could beconfigured to communicate via optical link 110 with ground-based station112.

In an example embodiment, balloons 102A to 102F are high-altitudeballoons, which are deployed in the stratosphere. At moderate latitudes,the stratosphere includes altitudes between approximately 10 kilometers(km) and 50 km altitude above the surface. At the poles, thestratosphere starts at an altitude of approximately 8 km. In an exampleembodiment, high-altitude balloons may be generally configured tooperate in an altitude range within the stratosphere that has relativelylow wind speed (e.g., between 5 and 20 miles per hour (mph)).

More specifically, in a high-altitude-balloon network, balloons 102A to102F may generally be configured to operate at altitudes between 18 kmand 25 km (although other altitudes are possible). This altitude rangemay be advantageous for several reasons. In particular, this layer ofthe stratosphere generally has relatively low wind speeds (e.g., windsbetween 5 and 20 mph) and relatively little turbulence. Further, whilethe winds between 18 km and 25 km may vary with latitude and by season,the variations can be modeled in a reasonably accurate manner.Additionally, altitudes above 18 km are typically above the maximumflight level designated for commercial air traffic. Therefore,interference with commercial flights is not a concern when balloons aredeployed between 18 km and 25 km.

To transmit data to another balloon, a given balloon 102A to 102F may beconfigured to transmit an optical signal via an optical link 104. In anexample embodiment, a given balloon 102A to 102F may use one or morehigh-power light-emitting diodes (LEDs) to transmit an optical signal.Alternatively, some or all of balloons 102A to 102F may include lasersystems for free-space optical communications over optical links 104.Other types of free-space optical communication are possible. Further,in order to receive an optical signal from another balloon via anoptical link 104, a given balloon 102A to 102F may include one or moreoptical receivers. Additional details of example balloons are discussedin greater detail below, with reference to FIG. 3.

In a further aspect, balloons 102A to 102F may utilize one or more ofvarious different RF air-interface protocols for communication withground-based stations 106 and 112 via respective RF links 108. Forinstance, some or all of balloons 102A to 102F may be configured tocommunicate with ground-based stations 106 and 112 using protocolsdescribed in IEEE 802.11 (including any of the IEEE 802.11 revisions),various cellular protocols such as GSM, CDMA, UMTS, EV-DO, WiMAX, and/orLTE, and/or one or more propriety protocols developed for balloon-groundRF communication, among other possibilities.

In a further aspect, there may be scenarios where RF links 108 do notprovide a desired link capacity for balloon-to-ground communications.For instance, increased capacity may be desirable to provide backhaullinks from a ground-based gateway, and in other scenarios as well.Accordingly, an example network may also include downlink balloons,which could provide a high-capacity air-ground link.

For example, in balloon network 100, balloon 102F is configured as adownlink balloon. Like other balloons in an example network, a downlinkballoon 102F may be operable for optical communication with otherballoons via optical links 104. However, a downlink balloon 102F mayalso be configured for free-space optical communication with aground-based station 112 via an optical link 110. Optical link 110 maytherefore serve as a high-capacity link (as compared to an RF link 108)between the balloon network 100 and the ground-based station 112.

Note that in some implementations, a downlink balloon 102F mayadditionally be operable for RF communication with ground-based stations106. In other cases, a downlink balloon 102F may only use an opticallink for balloon-to-ground communications. Further, while thearrangement shown in FIG. 1 includes just one downlink balloon 102F, anexample balloon network can also include multiple downlink balloons. Onthe other hand, a balloon network can also be implemented without anydownlink balloons.

In other implementations, a downlink balloon may be equipped with aspecialized, high-bandwidth RF communication system forballoon-to-ground communications, instead of, or in addition to, afree-space optical communication system. The high-bandwidth RFcommunication system may take the form of an ultra-wideband system,which may provide an RF link with substantially the same capacity as oneof the optical links 104. Other forms are also possible.

Ground-based stations, such as ground-based stations 106 and/or 112, maytake various forms. Generally, a ground-based station may includecomponents such as transceivers, transmitters, and/or receivers forcommunication via RF links and/or optical links with a balloon network.Further, a ground-based station may use various air-interface protocolsin order to communicate with a balloon 102A to 102F over an RF link 108.As such, ground-based stations 106 and 112 may be configured as anaccess point via which various devices can connect to balloon network100. Ground-based stations 106 and 112 may have other configurationsand/or serve other purposes without departing from the scope of theinvention.

In a further aspect, some or all of balloons 102A to 102F could beconfigured to establish a communication link with space-based satellitesin addition to, or as an alternative to, a ground-based communicationlink. In some embodiments, a balloon may communicate with a satellitevia an optical link. However, other types of satellite communicationsare possible.

Further, some ground-based stations, such as ground-based stations 106and 112, may be configured as gateways between balloon network 100 andone or more other networks. Such ground-based stations 106 and 112 maythus serve as an interface between the balloon network and the Internet,a cellular service provider's network, and/or other types of networks.Variations on this configuration and other configurations ofground-based stations 106 and 112 are also possible.

2a) Mesh Network Functionality

As noted, balloons 102A to 102F may collectively function as a meshnetwork. More specifically, since balloons 102A to 102F may communicatewith one another using free-space optical links, the balloons maycollectively function as a free-space optical mesh network.

In a mesh-network configuration, each balloon 102A to 102F may functionas a node of the mesh network, which is operable to receive datadirected to it and to route data to other balloons. As such, data may berouted from a source balloon to a destination balloon by determining anappropriate sequence of optical links between the source balloon and thedestination balloon. These optical links may be collectively referred toas a “lightpath” for the connection between the source and destinationballoons. Further, each of the optical links may be referred to as a“hop” on the lightpath.

To operate as a mesh network, balloons 102A to 102F may employ variousrouting techniques and self-healing algorithms. In some embodiments, aballoon network 100 may employ adaptive or dynamic routing, where alightpath between a source and destination balloon is determined andset-up when the connection is needed, and released at a later time.Further, when adaptive routing is used, the lightpath may be determineddynamically depending upon the current state, past state, and/orpredicted state of the balloon network.

In addition, the network topology may change as the balloons 102A to102F move relative to one another and/or relative to the ground.Accordingly, an example balloon network 100 may apply a mesh protocol toupdate the state of the network as the topology of the network changes.For example, to address the mobility of the balloons 102A to 102F,balloon network 100 may employ and/or adapt various techniques that areemployed in mobile ad hoc networks (MANETs). Other examples are possibleas well.

In some implementations, a balloon network 100 may be configured as atransparent mesh network. More specifically, in a transparent balloonnetwork, the balloons may include components for physical switching thatis entirely optical, without any electrical components involved in thephysical routing of optical signals. Thus, in a transparentconfiguration with optical switching, signals travel through a multi-hoplightpath that is entirely optical.

In other implementations, the balloon network 100 may implement afree-space optical mesh network that is opaque. In an opaqueconfiguration, some or all balloons 102A to 102F may implementoptical-electrical-optical (OEO) switching. For example, some or allballoons may include optical cross-connects (OXCs) for OEO conversion ofoptical signals. Other opaque configurations are also possible.Additionally, network configurations are possible that include routingpaths with both transparent and opaque sections.

In a further aspect, balloons in an example balloon network 100 mayimplement wavelength division multiplexing (WDM), which may help toincrease link capacity. When WDM is implemented with transparentswitching, physical lightpaths through the balloon network may besubject to the “wavelength continuity constraint.” More specifically,because the switching in a transparent network is entirely optical, itmay be necessary to assign the same wavelength for all optical links ona given lightpath.

An opaque configuration, on the other hand, may avoid the wavelengthcontinuity constraint. In particular, balloons in an opaque balloonnetwork may include the OEO switching systems operable for wavelengthconversion. As a result, balloons can convert the wavelength of anoptical signal at each hop along a lightpath. Alternatively, opticalwavelength conversion could take place at only selected hops along thelightpath.

Further, various routing algorithms may be employed in an opaqueconfiguration. For example, to determine a primary lightpath and/or oneor more diverse backup lightpaths for a given connection, exampleballoons may apply or consider shortest-path routing techniques such asDijkstra's algorithm and k-shortest path, and/or edge and node-diverseor disjoint routing such as Suurballe's algorithm, among others.Additionally or alternatively, techniques for maintaining a particularquality of service (QoS) may be employed when determining a lightpath.Other techniques are also possible.

2b) Station-Keeping Functionality

In an example embodiment, a balloon network 100 may implementstation-keeping functions to help provide a desired network topology.For example, station-keeping may involve each balloon 102A to 102Fmaintaining and/or moving into a certain position relative to one ormore other balloons in the network (and possibly in a certain positionrelative to the ground). As part of this process, each balloon 102A to102F may implement station-keeping functions to determine its desiredpositioning within the desired topology, and if necessary, to determinehow to move to the desired position.

The desired topology may vary depending upon the particularimplementation. In some cases, balloons may implement station-keeping toprovide a substantially uniform topology. In such cases, a given balloon102A to 102F may implement station-keeping functions to position itselfat substantially the same distance (or within a certain range ofdistances) from adjacent balloons in the balloon network 100.

In other cases, a balloon network 100 may have a non-uniform topology.For instance, example embodiments may involve topologies where balloonsare distributed more or less densely in certain areas, for variousreasons. As an example, to help meet the higher bandwidth demands thatare typical in urban areas, balloons may be clustered more densely overurban areas. For similar reasons, the distribution of balloons may bedenser over land than over large bodies of water. Many other examples ofnon-uniform topologies are possible.

In a further aspect, the topology of an example balloon network may beadaptable. In particular, station-keeping functionality of exampleballoons may allow the balloons to adjust their respective positioningin accordance with a change in the desired topology of the network. Forexample, one or more balloons could move to new positions to increase ordecrease the density of balloons in a given area. Other examples arepossible.

In some embodiments, a balloon network 100 may employ an energy functionto determine if and/or how balloons should move to provide a desiredtopology. In particular, the state of a given balloon and the states ofsome or all nearby balloons may be input to an energy function. Theenergy function may apply the current states of the given balloon andthe nearby balloons to a desired network state (e.g., a statecorresponding to the desired topology). A vector indicating a desiredmovement of the given balloon may then be determined by determining thegradient of the energy function. The given balloon may then determineappropriate actions to take in order to effectuate the desired movement.For example, a balloon may determine an altitude adjustment oradjustments such that winds will move the balloon in the desired manner.

2c) Control of Balloons in a Balloon Network

In some embodiments, mesh networking and/or station-keeping functionsmay be centralized. For example, FIG. 2 is a block diagram illustratinga balloon-network control system, according to an example embodiment. Inparticular, FIG. 2 shows a distributed control system, which includes acentral control system 200 and a number of regional control-systems 202Ato 202B. Such a control system may be configured to coordinate certainfunctionality for balloon network 204, and as such, may be configured tocontrol and/or coordinate certain functions for balloons 206A to 206I.

In the illustrated embodiment, central control system 200 may beconfigured to communicate with balloons 206A to 206I via a number ofregional control systems 202A to 202C. These regional control systems202A to 202C may be configured to receive communications and/oraggregate data from balloons in the respective geographic areas thatthey cover, and to relay the communications and/or data to centralcontrol system 200. Further, regional control systems 202A to 202C maybe configured to route communications from central control system 200 tothe balloons in their respective geographic areas. For instance, asshown in FIG. 2, regional control system 202A may relay communicationsand/or data between balloons 206A to 206C and central control system200, regional control system 202B may relay communications and/or databetween balloons 206D to 206F and central control system 200, andregional control system 202C may relay communications and/or databetween balloons 206G to 206I and central control system 200.

In order to facilitate communications between the central control system200 and balloons 206A to 206I, certain balloons may be configured asdownlink balloons, which are operable to communicate with regionalcontrol systems 202A to 202C. Accordingly, each regional control system202A to 202C may be configured to communicate with the downlink balloonor balloons in the respective geographic area it covers. For example, inthe illustrated embodiment, balloons 206A, 206F, and 206I are configuredas downlink balloons. As such, regional control systems 202A to 202C mayrespectively communicate with balloons 206A, 206F, and 206I via opticallinks 206, 208, and 210, respectively.

In the illustrated configuration, only some of balloons 206A to 206I areconfigured as downlink balloons. The balloons 206A, 206F, and 206I thatare configured as downlink balloons may relay communications fromcentral control system 200 to other balloons in the balloon network,such as balloons 206B to 206E, 206G, and 206H. However, it should beunderstood that in some implementations, it is possible that allballoons may function as downlink balloons. Further, while FIG. 2 showsmultiple balloons configured as downlink balloons, it is also possiblefor a balloon network to include only one downlink balloon, or possiblyeven no downlink balloons.

Note that a regional control system 202A to 202C may in fact just be aparticular type of ground-based station that is configured tocommunicate with downlink balloons (e.g., such as ground-based station112 of FIG. 1). Thus, while not shown in FIG. 2, a control system may beimplemented in conjunction with other types of ground-based stations(e.g., access points, gateways, etc.).

In a centralized control arrangement, such as that shown in FIG. 2, thecentral control system 200 (and possibly regional control systems 202Ato 202C as well) may coordinate certain mesh-networking functions forballoon network 204. For example, balloons 206A to 206I may send thecentral control system 200 certain state information, which the centralcontrol system 200 may utilize to determine the state of balloon network204. The state information from a given balloon may include locationdata, optical-link information (e.g., the identity of other balloonswith which the balloon has established an optical link, the bandwidth ofthe link, wavelength usage and/or availability on a link, etc.), winddata collected by the balloon, and/or other types of information.Accordingly, the central control system 200 may aggregate stateinformation from some or all of the balloons 206A to 206I in order todetermine an overall state of the network.

The overall state of the network may then be used to coordinate and/orfacilitate certain mesh-networking functions such as determininglightpaths for connections. For example, the central control system 200may determine a current topology based on the aggregate stateinformation from some or all of the balloons 206A to 206I. The topologymay provide a picture of the current optical links that are available inballoon network and/or the wavelength availability on the links. Thistopology may then be sent to some or all of the balloons so that arouting technique may be employed to select appropriate lightpaths (andpossibly backup lightpaths) for communications through the balloonnetwork 204.

In a further aspect, the central control system 200 (and possiblyregional control systems 202A to 202C as well) may also coordinatecertain station-keeping functions for balloon network 204. For example,the central control system 200 may input state information that isreceived from balloons 206A to 206I to an energy function, which mayeffectively compare the current topology of the network to a desiredtopology, and provide a vector indicating a direction of movement (ifany) for each balloon, such that the balloons can move towards thedesired topology. Further, the central control system 200 may usealtitudinal wind data to determine respective altitude adjustments thatmay be initiated to achieve the movement towards the desired topology.The central control system 200 may provide and/or support otherstation-keeping functions as well.

FIG. 2 shows a distributed arrangement that provides centralizedcontrol, with regional control systems 202A to 202C coordinatingcommunications between a central control system 200 and a balloonnetwork 204. Such an arrangement may be useful to provide centralizedcontrol for a balloon network that covers a large geographic area. Insome embodiments, a distributed arrangement may even support a globalballoon network that provides coverage everywhere on earth. Of course, adistributed-control arrangement may be useful in other scenarios aswell.

Further, it should be understood that other control-system arrangementsare also possible. For instance, some implementations may involve acentralized control system with additional layers (e.g., sub-regionsystems within the regional control systems, and so on). Alternatively,control functions may be provided by a single, centralized, controlsystem, which communicates directly with one or more downlink balloons.

In some embodiments, control and coordination of a balloon network maybe shared by a ground-based control system and a balloon network tovarying degrees, depending upon the implementation. In fact, in someembodiments, there may be no ground-based control systems. In such anembodiment, all network control and coordination functions may beimplemented by the balloon network itself. For example, certain balloonsmay be configured to provide the same or similar functions as centralcontrol system 200 and/or regional control systems 202A to 202C. Otherexamples are also possible.

Furthermore, control and/or coordination of a balloon network may bede-centralized. For example, each balloon may relay state informationto, and receive state information from, some or all nearby balloons.Further, each balloon may relay state information that it receives froma nearby balloon to some or all nearby balloons. When all balloons doso, each balloon may be able to individually determine the state of thenetwork. Alternatively, certain balloons may be designated to aggregatestate information for a given portion of the network. These balloons maythen coordinate with one another to determine the overall state of thenetwork.

Further, in some aspects, control of a balloon network may be partiallyor entirely localized, such that it is not dependent on the overallstate of the network. For example, individual balloons may implementstation-keeping functions that only consider nearby balloons. Inparticular, each balloon may implement an energy function that takesinto account its own state and the states of nearby balloons. The energyfunction may be used to maintain and/or move to a desired position withrespect to the nearby balloons, without necessarily considering thedesired topology of the network as a whole. However, when each balloonimplements such an energy function for station-keeping, the balloonnetwork as a whole may maintain and/or move towards the desiredtopology.

As an example, each balloon A may receive distance information d₁ tod_(k) with respect to each of its k closest neighbors. Each balloon Amay treat the distance to each of the k balloons as a virtual springwith vector representing a force direction from the first nearestneighbor balloon i toward balloon A and with force magnitudeproportional to d_(i). The balloon A may sum each of the k vectors andthe summed vector is the vector of desired movement for balloon A.Balloon A may attempt to achieve the desired movement by controlling itsaltitude.

Alternatively, this process could assign the force magnitude of each ofthese virtual forces equal to d_(i)×d_(i), for instance. Otheralgorithms for assigning force magnitudes for respective balloons in amesh network are possible.

In another embodiment, a similar process could be carried out for eachof the k balloons and each balloon could transmit its planned movementvector to its local neighbors. Further rounds of refinement to eachballoon's planned movement vector can be made based on the correspondingplanned movement vectors of its neighbors. It will be evident to thoseskilled in the art that other algorithms could be implemented in aballoon network in an effort to maintain a set of balloon spacingsand/or a specific network capacity level over a given geographiclocation.

2d) Example Balloon Configuration

Various types of balloon systems may be incorporated in an exampleballoon network. As noted above, an example embodiment may utilizehigh-altitude balloons, which could typically operate in an altituderange between 17 km and 25 km. FIG. 3 shows a high-altitude balloon 300,according to an example embodiment. As shown, the balloon 300 includesan envelope 302, a skirt 304, a payload 306, and a cut-down system 308,which is attached between the balloon 302 and payload 304.

The envelope 302 and skirt 304 may take various forms, which may becurrently well-known or yet to be developed. For instance, the envelope302 and/or skirt 304 may be made of materials including metalized Mylaror BoPet. Additionally or alternatively, some or all of the envelope 302and/or skirt 304 may be constructed from a highly-flexible latexmaterial or a rubber material such as chloroprene. Other materials arealso possible. Further, the shape and size of the envelope 302 and skirt304 may vary depending upon the particular implementation. Additionally,the envelope 302 may be filled with various different types of gases,such as helium and/or hydrogen. Other types of gases are possible aswell.

The payload 306 of balloon 300 may include a processor 312 and on-boarddata storage, such as memory 314. The memory 314 may take the form of orinclude a non-transitory computer-readable medium. The non-transitorycomputer-readable medium may have instructions stored thereon, which canbe accessed and executed by the processor 312 in order to carry out theballoon functions described herein. Thus, processor 312, in conjunctionwith instructions stored in memory 314, and/or other components, mayfunction as a controller of balloon 300.

The payload 306 of balloon 300 may also include various other types ofequipment and systems to provide a number of different functions. Forexample, payload 306 may include an optical communication system 316,which may transmit optical signals via an ultra-bright LED system 320,and which may receive optical signals via an optical-communicationreceiver 322 (e.g., a photodiode receiver system). Further, payload 306may include an RF communication system 318, which may transmit and/orreceive RF communications via an antenna system 340.

The payload 306 may also include a power supply 326 to supply power tothe various components of balloon 300. The power supply 326 couldinclude a rechargeable battery. In other embodiments, the power supply326 may additionally or alternatively represent other means known in theart for producing power. In addition, the balloon 300 may include asolar power generation system 327. The solar power generation system 327may include solar panels and could be used to generate power thatcharges and/or is distributed by the power supply 326.

The payload 306 may additionally include a positioning system 324. Thepositioning system 324 could include, for example, a global positioningsystem (GPS), an inertial navigation system, and/or a star-trackingsystem. The positioning system 324 may additionally or alternativelyinclude various motion sensors (e.g., accelerometers, magnetometers,gyroscopes, and/or compasses).

The positioning system 324 may additionally or alternatively include oneor more video and/or still cameras, and/or various sensors for capturingenvironmental data.

Some or all of the components and systems within payload 306 may beimplemented in a radiosonde or other probe, which may be operable tomeasure, e.g., pressure, altitude, geographical position (latitude andlongitude), temperature, relative humidity, and/or wind speed and/orwind direction, among other information.

As noted, balloon 300 includes an ultra-bright LED system 320 forfree-space optical communication with other balloons. As such, opticalcommunication system 316 may be configured to transmit a free-spaceoptical signal by modulating the ultra-bright LED system 320. Theoptical communication system 316 may be implemented with mechanicalsystems and/or with hardware, firmware, and/or software. Generally, themanner in which an optical communication system is implemented may vary,depending upon the particular application. The optical communicationsystem 316 and other associated components are described in furtherdetail below.

In a further aspect, balloon 300 may be configured for altitude control.For instance, balloon 300 may include a variable buoyancy system, whichis configured to change the altitude of the balloon 300 by adjusting thevolume and/or density of the gas in the balloon 300. A variable buoyancysystem may take various forms, and may generally be any system that canchange the volume and/or density of gas in the envelope 302.

In an example embodiment, a variable buoyancy system may include abladder 310 that is located inside of envelope 302. The bladder 310could be an elastic chamber configured to hold liquid and/or gas.Alternatively, the bladder 310 need not be inside the envelope 302. Forinstance, the bladder 310 could be a rigid bladder that could bepressurized well beyond neutral pressure. The buoyancy of the balloon300 may therefore be adjusted by changing the density and/or volume ofthe gas in bladder 310. To change the density in bladder 310, balloon300 may be configured with systems and/or mechanisms for heating and/orcooling the gas in bladder 310. Further, to change the volume, balloon300 may include pumps or other features for adding gas to and/orremoving gas from bladder 310. Additionally or alternatively, to changethe volume of bladder 310, balloon 300 may include release valves orother features that are controllable to allow gas to escape from bladder310. Multiple bladders 310 could be implemented within the scope of thisdisclosure. For instance, multiple bladders could be used to improveballoon stability.

In an example embodiment, the envelope 302 could be filled with helium,hydrogen or another lighter-than-air gas or combination of gases. Wheninflated, the envelope 302 could thus have an associated upward buoyancyforce. In such an embodiment, air in the bladder 310 could be considereda ballast tank that may have an associated downward ballast force. Inanother example embodiment, the amount of air in the bladder 310 couldbe changed by pumping air (e.g., with an air compressor) into and out ofthe bladder 310. By adjusting the amount of air in the bladder 310, theballast force may be controlled. In some embodiments, the ballast forcemay be used, in part, to counteract the buoyancy force and/or to providealtitude stability.

In other embodiments, the envelope 302 could be substantially rigid andinclude an enclosed volume. Air could be evacuated from envelope 302while the enclosed volume is substantially maintained. In other words,at least a partial vacuum could be created and maintained within theenclosed volume. Thus, the envelope 302 and the enclosed volume couldbecome lighter than air and provide a buoyancy force. In yet otherembodiments, air or another material could be controllably introducedinto the partial vacuum of the enclosed volume in an effort to adjustthe overall buoyancy force and/or to provide altitude control.

In another embodiment, a portion of the envelope 302 could be a firstcolor (e.g., black) and/or a first material from the rest of envelope302, which may have a second color (e.g., white) and/or a secondmaterial. For instance, the first color and/or first material could beconfigured to absorb a relatively larger amount of solar energy than thesecond color and/or second material. Thus, rotating the balloon suchthat the first material is facing the sun may act to heat the envelope302 as well as the gas inside the envelope 302. In this way, thebuoyancy force of the envelope 302 may increase. By rotating the balloonsuch that the second material is facing the sun, the temperature of gasinside the envelope 302 may decrease. Accordingly, the buoyancy forcemay decrease. In this manner, the buoyancy force of the balloon could beadjusted by changing the temperature/volume of gas inside the envelope302 using solar energy. In such embodiments, it is possible that abladder 310 may not be a necessary element of balloon 300. Thus, invarious contemplated embodiments, altitude control of balloon 300 couldbe achieved, at least in part, by adjusting the rotation of the balloonwith respect to the sun.

Further, a balloon 306 may include a navigation system (not shown). Thenavigation system may implement station-keeping functions to maintainposition within and/or move to a position in accordance with a desiredtopology. In particular, the navigation system may use altitudinal winddata to determine altitudinal adjustments that result in the windcarrying the balloon in a desired direction and/or to a desiredlocation. The altitude-control system may then make adjustments to thedensity of the balloon chamber in order to effectuate the determinedaltitudinal adjustments and cause the balloon to move laterally to thedesired direction and/or to the desired location. Alternatively, thealtitudinal adjustments may be computed by a ground-based orsatellite-based control system and communicated to the high-altitudeballoon. In other embodiments, specific balloons in a heterogeneousballoon network may be configured to compute altitudinal adjustments forother balloons and transmit the adjustment commands to those otherballoons.

As shown, the balloon 300 also includes a cut-down system 308. Thecut-down system 308 may be activated to separate the payload 306 fromthe rest of balloon 300. The cut-down system 308 could include at leasta connector, such as a balloon cord, connecting the payload 306 to theenvelope 302 and a means for severing the connector (e.g., a shearingmechanism or an explosive bolt). In an example embodiment, the ballooncord, which may be nylon, is wrapped with a nichrome wire. A currentcould be passed through the nichrome wire to heat it and melt the cord,cutting the payload 306 away from the envelope 302.

The cut-down functionality may be utilized anytime the payload needs tobe accessed on the ground, such as when it is time to remove balloon 300from a balloon network, when maintenance is due on systems withinpayload 306, and/or when power supply 326 needs to be recharged orreplaced.

In an alternative arrangement, a balloon may not include a cut-downsystem. In such an arrangement, the navigation system may be operable tonavigate the balloon to a landing location, in the event the balloonneeds to be removed from the network and/or accessed on the ground.Further, it is possible that a balloon may be self-sustaining, such thatit does not need to be accessed on the ground. In yet other embodiments,in-flight balloons may be serviced by specific service balloons oranother type of service aerostat or service aircraft.

4. Illustrative Systems

A balloon-launching system may include a shell structure, a balloon, alift element, and a control system. The balloon-launching system mayoptionally include a movement element. Accordingly, illustrative systemsmay be described in reference to FIGS. 4-8. FIG. 4 is a simplified blockdiagram illustrating a shell-structure 410, a balloon 430, a liftelement 450, an optional movement element 470, and a control system 490,according to an example embodiment.

The shell structure 410 may include a communication system 412, at leasttwo shell portions 414, an actuation device 416, and/or a sensor 418.The shell portions 414 could include at least two shell elements thatare configured to open and close. The shell portions 414 may takevarious shapes. For example, the shell portions 414 may be shaped like aclam shell. Alternatively, the shell portions 414 may be shaped likeseveral flower petals that may open and close. Other geometries forshell portions 414 will be obvious to those skilled in the art. Theshell portions 414 may be operable to close around the balloon 430 so asto protect the balloon 430. Specifically, while enclosed by the shellstructure 410, the balloon 430 may be substantially protected from windgusts and other environmental elements in the external environmentoutside the shell structure 410. Optionally, the shell portions 414 maybe operable to open so as to allow the balloon 430 to launch.

The shell structure 410 may include at least an inner portion and anouter portion. The inner portion may include a soft material configuredto reduce a friction force when in contact with the envelope 432. Theouter portion may include a rigid material configured to resist a windforce in the external environment. In an illustrative embodiment, theinner portion may include a non-stick coating material such as Teflon.Other materials for the inner portion of the shell structure 410 may beutilized so as to minimize damage to the envelope 432. The outer portionmay include rigid materials like engineered composites (e.g. fiberglass,carbon fiber-reinforced polymers, metal matrix composites, and/orceramic matrix composites). In general, the shell structure 410 mayinclude fire-retardant or fire-resistant materials.

The actuation device 416 may be coupled to the at least two shellportions 414. The actuation device 416 may be configured to open andclose the at least two shell portions 414. Accordingly, the actuationdevice 416 may include at least one hydraulic piston. The actuationdevice 416 may be operable using other forms of actuation (e.g.electro-magnetic, pneumatic, etc.) The actuation device 416 may becoupled to other parts of the system 400. For example, the actuationdevice may be coupled to the movement element 470.

The balloon 430 may be similar or identical to balloon 300 asillustrated and described in reference to FIG. 3. Specifically, theballoon 430 may include an envelope 432, a payload 434, and acommunication system 436. The balloon 430 may be operable in a balloonnetwork as described herein. Furthermore, the balloon 430 may beconfigured to be positioned within the shell structure 410. Wheninitially positioned within the shell structure 410, the envelope 432may be uninflated and compressed. In other words, the envelope 432 maybe folded or packed into a package for easier shipping and/or handling.The balloon 430 may include a tether that may be coupled to an anchor.The anchor may be a physical weight or may be an anchor point on theshell structure 410. The tether may be configured to physically tie downthe balloon to the shell structure while inflated. The tether mayadditionally be configured to be controllably decoupled from the shellstructure 410 and/or the balloon 430. For example, in response to alaunch command, for instance from control system 490, the tether may bedecoupled so as to allow the balloon 430 to launch.

The system may additionally include a lift element 450. The lift element450 may include a lift winch 452, a fill hose 454, and a communicationsystem 456. The lift element 450 may be configured to unpack theenvelope 432. The lift element 450 may also be configured to fill theenvelope 432 with lift gas. In an illustrative embodiment, the liftelement 450 may include a gantry crane. The gantry crane may beconfigured to lift the envelope 432 while the balloon 430 is enclosed bythe shell structure 410. For example, the lift winch 452 may beconfigured to pass through an opening in the shell structure 410, coupleto the envelope 432, and pull the envelope 432 in a directionperpendicular to the ground. The lift winch 452 may include elementssuch as a winch motor, winch cable, and a hook or another deviceconfigured to couple the lift winch 452 to the envelope. In such anembodiment, forces exerted on the envelope 432 by the lift winch 452 maystretch the envelope 432 in a vertical direction so as to unpack anddecompress the envelope 432. The fill hose 454 may be optionallyconfigured to be coupled to the lift winch 452. The fill hose 454 may beconfigured to deliver lift gas to the envelope 432. The fill hose 454and the lift winch 452 may be configured to couple to the envelope 432at the same location. Alternatively, the fill hose 454 and the liftwinch 452 may be configured to couple to the envelope 432 at separatelocations. Furthermore, the fill hose 454 and the lift winch 452 neednot be separate physical elements. For example, the fill hose 454 may beconfigured to stretch the envelope 432 as well as fill the envelope 432with lift gas.

The system may optionally include a movement element 470. The movementelement 470 may include data storage 472, program instructions 474, anda communication system 476. The movement element 470 may include avehicle, such as a forklift, a truck, a car, a ship, or any othervehicle configured to lift and move a load. In an illustrativeembodiment, the movement element 470 may include power-operated forks orprongs configured to couple to the shell structure 410. The movementelement 470 may be configured to move the shell structure 410 and,optionally, the balloon 430. Specifically, the movement element 470 maybe configured to move the shell structure 410 (and optionally enclosedballoon 430) in a plane substantially parallel to the ground.

The control system 490 may include data storage 492, programinstructions 494, and a communication system 496. The communicationsystem 496 may be configured to communicate with any or all ofcommunication systems 412, 436, 456, and 476. In other words, thecontrol system 490 could be configured to transmit and/or receiveinformation from any of the shell structure 410, balloon 430, liftelement 450, and/or the movement element 470. The control system 490 maybe configured to cause the lift element 450 to unpack and fill theenvelope 432 while the shell structure 410 encloses the balloon 430.Additionally, the control system 490 may be optionally configured todetermine a wind direction and a wind velocity of wind in an externalenvironment outside the shell structure 410. In an illustrativeembodiment, a wind sensor may provide wind data to the control system490. Based on the received data, the control system 490 may beoptionally configured to calculate, predict, and/or estimate windconditions outside the shell structure 410.

The control system 490 may be optionally configured to cause themovement element 470 to move along the ground at a velocity and in adirection substantially matching the determined wind velocity and thewind direction. In so doing, a zero-wind condition may result. In otherwords, a zero-wind condition may result from moving the movement element470 at a velocity and in a direction matching external wind conditions.In response to the zero-wind condition, the control system 490 may beoptionally configured to cause the shell structure to open. In anillustrative embodiment, the control system 490 may optionally determinea zero-wind condition while the shell structure 410 is moving at avelocity and in a direction substantially matching the external windconditions. Upon determining the zero-wind condition, the control system490 may transmit a signal to cause the shell structure 410 to open.Furthermore, the control system 490 may be optionally configured tocause the balloon 430 to launch in response to the zero-wind condition.In an illustrative embodiment, the control system 490 may transmit asignal to cause the balloon 430 to launch after opening the shellstructure 410.

5. Illustrative Methods

A method 900 is provided for unpacking, filling, and launching a balloonunder zero-wind conditions. The method may be performed using any of theapparatus shown in FIGS. 1-4 and described above. However, otherconfigurations may be used. FIG. 9 illustrates the functions in anillustrative method 900 with reference to FIGS. 3-8. It is understoodthat in other embodiments, the functions may appear in different orderand functions could be added or subtracted.

Function 902 includes providing a balloon positioned substantiallywithin a shell structure. The balloon includes an envelope in aninitially packed state. The balloon may be similar or identical toballoon 300 in FIG. 3 or a prepackaged balloon 502 as shown in FIG. 5.The shell structure may similar or identical to shell structure 410 inFIG. 4 or a shell structure 504 as shown in FIG. 5. In an illustrativeembodiment, providing the balloon substantially within the shellstructure may include loading a prepackaged balloon 502 into the shellstructure 504 as illustrated in FIG. 5. For example, as shown in FIG. 3,the uninflated envelope 302 and other portions of the balloon 300 may beinitially packed or compressed within a package. The prepackaged balloon502 may be loaded into the shell structure 504 in preparation forlaunch. After loading the prepackaged balloon 502 into the shellstructure 504, the shell structure 504 may be substantially close aroundthe prepackaged balloon 502.

Function 904 includes while the balloon is substantially within theshell structure, unpacking the envelope in a direction substantiallyperpendicular to a ground surface so as to stretch the envelope. In anillustrative embodiment, a lift element 602 may couple to the envelope604 as illustrated in FIG. 6. The lift element 602 may stretch theuninflated (or partially inflated) envelope 604 in a vertical directionso as to unpack and loosen the envelope from its packaging 606. The liftelement 602 may include a lift winch 608 and fill hose 610 that may passthrough an opening near the top of the shell structure 612 when theshell structure 614 is closed. In some embodiments, the lift element 602may be supported by a gantry crane 620 or another structure configuredto support lifting devices.

Function 906 includes while the balloon is substantially within theshell structure, filling the envelope with a lift gas. As describedabove in reference to FIG. 6, the lift element may include a fill hose610 that may couple to the envelope 604. The fill hose 610 may inflatethe envelope 604 with lift gas (e.g. helium, hydrogen, hot air, etc.).

Although functions 904 and 906 are described above as discretefunctions, they may occur simultaneously. For example, forces applied bylift winch 608 may stretch the envelope 604 upwards out of its packaging606 while the envelope 604 is being filled with lift gas from the fillhose 610. Additionally or alternatively, the respective steps need notbe carried out to completion at any one time. For example, functions 904and 906 could be partially performed (e.g., the envelope 604 not beingfully stretched or not fully inflated) several times in an alternatingfashion so as to gradually stretch and fill the envelope 604. In otherwords, initially the envelope 604 may be partially stretched by forcesapplied the lift winch 608. Then, the envelope 604 may be partiallyinflated by the fill hose 610, and so on until the envelope is fullyinflated. FIG. 7 depicts a scenario with an inflated envelope 702 beforeballoon launch.

Some embodiments may optionally include further functions that may becarried out within the scope of the method. For example, Function 908includes determining, based on wind data associated with an externalenvironment outside the shell structure, a wind direction and a windvelocity of wind in the external environment. The determination of thewind direction and the wind velocity may be carried out by the controlsystem 490 as described in reference to FIG. 4. Alternatively oradditionally, a different computing system may determine the winddirection and the wind velocity. The wind data may be obtained by one ormore wind sensors. In an illustrative embodiment depicted in FIG. 8, awind sensor 804 may be located on the shell structure 802. However, thewind sensor may be located elsewhere. For instance, a wind sensor 806may be positioned on a movement element 810 or a wind sensor 808 may befixed to the ground. Furthermore, wind sensors may be positioned inseveral different locations.

The determination of the wind direction and the wind velocity mayinclude a direct measurement of the wind in the external environment.For example, if the wind sensor 808 is fixed to the ground, thedetermination of the wind direction and the wind velocity may be similarto conventional weather instrumentation. Alternatively or additionally,the determination of the wind direction and the wind velocity mayincorporate movement of the shell structure 802 and/or the movementelement 810. For example, if the wind sensor 806 is coupled to themovement element 810, and the movement element 810 is moving, thedetermination of the wind direction and wind velocity in the externalenvironment may be affected by the relative movement of the wind sensor806. Thus, in an illustrative embodiment, the determination of the winddirection and wind velocity may include adding or subtracting a movementvector (direction and velocity) to the measured wind direction and windvelocity.

Function 910 includes causing the shell structure to move in a directionand at a velocity resulting in a substantial zero-wind condition. Forexample, the zero-wind condition may include a condition in which theshell structure 802 is moving in a direction about the wind directionand the shell structure 802 is moving at a velocity about the windvelocity. In an illustrative embodiment, the control system 490 maycause the movement element 810 to move the shell structure 802 in adirection and at a velocity in about the wind direction and at about thewind velocity. It is understood that function 910 may be carried outsimultaneously with other steps in the disclosed method. For example,the shell structure 802 may be moving while carrying out function 908(determining the wind direction and wind velocity). Additionally, theshell structure 802 may be moving along the ground while the shellstructure 802 is caused to open, as described below.

Function 912 includes, in response to the substantial zero-windcondition, causing the shell structure 802 to open such that the balloon820 is exposed to the external environment, and launching the balloon820. In an illustrative embodiment, depicted in FIG. 8, the shellstructure 802 (and thus the balloon 820) may be traveling atapproximately the same velocity and direction as the wind in theexternal environment, which may result in a zero-wind condition. In sucha case, the control system 490 may cause the shell structure 802 to openand expose the balloon 820 to the external environment. Causing theshell structure 802 to open may include the shell structure 802 openinglike two halves of a clamshell. Alternatively, the shell structure 802may open like a flower. Causing the shell structure 802 to open mayinclude causing an actuation device 830 to actuate the shell structureportions 840A and 840B to open. For example, the actuation device 830may include a hydraulic piston and the control system 490 may cause themovement element 810 to charge an auxiliary hydraulic line connected tothe hydraulic piston, causing the shell structure portions 840A and 840Bto open.

Subsequent to causing the shell structure 802 to open, the controlsystem 490 may cause the balloon 820 to launch. In an illustrativeembodiment, the control system 490 may send a launch signal to the shellstructure 802 and/or the balloon 820 so as to cause the tether 850 touncouple the balloon 820 from the shell structure 802 or anchor. As anexample, a current may be passed through a nichrome wire (not shown)wrapped around the tether 850 so as to sever the tether 850 and launchthe balloon 820.

6. Illustrative Non-Transitory Computer Readable Media

Some or all of the functions described above and illustrated in FIGS.5-9 may be performed by a computing device in response to the executionof instructions stored in a non-transitory computer readable medium. Thenon-transitory computer readable medium could be, for example, a randomaccess memory (RAM), a read-only memory (ROM), a flash memory, a cachememory, one or more magnetically encoded discs, one or more opticallyencoded discs, or any other form of non-transitory data storage. Thenon-transitory computer readable medium could also be distributed amongmultiple data storage elements, which could be remotely located fromeach other. In an illustrative embodiment, the non-transitory computerreadable medium may include program instructions 474 and/or programinstructions 494 as illustrated and described in reference to FIG. 4.The computing device that executes the stored instructions could be acomputing device, such as the processor 312 as described and illustratedin reference to FIG. 3. Alternatively, the processor could be an elementof the shell structure 410, the balloon 430, the movement element 470,the control system 490, and/or the lift element 450 as illustrated anddescribed in reference to FIG. 4. Optionally, the computing device thatexecutes the stored instructions could be another computing device, suchas a server in a server network, or a ground-based station.

The non-transitory computer readable medium may store instructionsexecutable by the any of the aforementioned processors to performvarious functions. The functions include causing an envelope of aballoon to be unpacked in a direction substantially perpendicular to aground surface so as to stretch the envelope. The balloon includes theenvelope in an initially packed state. The envelope in the initiallypacked state includes the envelope being uninflated. A shell structureencloses the balloon. The functions further include causing the envelopeto be filled with gas. The functions may optionally include determining,based on wind data associated with an external environment outside ashell structure enclosing a balloon, a wind direction and a windvelocity of wind in the external environment. The functions may furtherinclude causing the shell structure to move in a direction and at avelocity resulting in a substantial zero-wind condition. The zero-windcondition includes the direction being in about the wind direction andthe velocity being at about the wind velocity. The functions alsooptionally include, in response to the substantial zero-wind condition,causing the shell structure to open such that the balloon is exposed tothe external environment, and launching the balloon.

The non-transitory computer readable medium may include additionalfunctions such as causing a vehicle to move the shell structure.Additionally, the non-transitory computer readable medium may includefunctions that carry out some or all of method 900 as illustrated anddescribed in reference to FIG. 9.

The above detailed description describes various features and functionsof the disclosed systems, devices, and methods with reference to theaccompanying figures. While various aspects and embodiments have beendisclosed herein, other aspects and embodiments will be apparent tothose skilled in the art. The various aspects and embodiments disclosedherein are for purposes of illustration and are not intended to belimiting, with the true scope being indicated by the following claims.

What is claimed is:
 1. A method comprising: providing a balloonpositioned substantially within a shell structure, wherein the ballooncomprises an envelope in an initially packed state, wherein the envelopein the initially packed state comprises the envelope being uninflatedand compressed; while the balloon is substantially within the shellstructure, unpacking the envelope in a direction substantiallyperpendicular to a ground surface so as to stretch the envelope; andwhile the balloon is substantially within the shell structure, fillingthe envelope with a lift gas.
 2. The method of claim 1, wherein the liftgas comprises a lighter-than-air gas.
 3. The method of claim 1, whereinunpacking the envelope comprises unpacking the envelope with a liftwinch.
 4. The method of claim 3, wherein filling the envelope comprisesfilling the envelope with a fill hose coupled to the lift winch.
 5. Themethod of claim 4, wherein the shell structure comprises an opening andwherein the fill hose and the lift winch are configured to move throughthe opening.
 6. The method of claim 1 wherein the shell structurecomprises an anchor configured to couple the balloon to the shellstructure via a tether.
 7. A system comprising: a shell structureconfigured to substantially enclose a balloon and to open such that theballoon is exposed to an external environment, wherein the ballooncomprises an envelope in an initially packed state, wherein the envelopein the initially packed state comprises the envelope being uninflatedand compressed, wherein the external environment comprises environmentalconditions outside the shell structure; a lift element configured tounpack the envelope and fill the envelope, wherein unpacking theenvelope comprises stretching the envelope in a direction substantiallyperpendicular to a ground surface and wherein filling the envelopecomprises filling the envelope with a lift gas; and a control systemconfigured to: while the shell structure encloses the balloon, cause thelift element to unpack the envelope; and while the shell structureencloses the balloon, cause the lift element to fill the envelope. 8.The system of claim 7, wherein the shell structure comprises an innerportion and an outer portion, wherein the inner portion comprises a softmaterial configured to reduce a friction force when in contact with theenvelope and wherein the outer portion comprises a rigid materialconfigured to resist a wind force in the external environment.
 9. Thesystem of claim 7, wherein the shell structure comprises afire-retardant material.
 10. The system of claim 7, wherein the lift gascomprises a lighter-than-air gas.
 11. The system of claim 7, wherein theshell structure comprises at least two shell portions, wherein the atleast two shell portions are configured to substantially close aroundthe balloon and to substantially open so the balloon may launch.
 12. Thesystem of claim 11, wherein the shell structure comprises an actuationdevice coupled to the at least two shell portions and wherein theactuation device is configured to open and close the at least two shellportions.
 13. The system of claim 12, wherein the actuation devicecomprises at least one hydraulic piston.
 14. The system of claim 7,wherein the lift element comprises a gantry crane.
 15. The system ofclaim 7, wherein the balloon further comprises a payload.
 16. Anon-transitory computer-readable medium having stored thereininstructions that, when executed by a computing device, cause thecomputing device to perform functions comprising: causing an envelope ofa balloon to be unpacked in a direction substantially perpendicular to aground surface so as to stretch the envelope, wherein the ballooncomprises the envelope in an initially packed state, wherein theenvelope in the initially packed state comprises the envelope beinguninflated and wherein a shell structure encloses the balloon; andcausing the envelope to be filled with a lift gas.
 17. Thenon-transitory computer readable medium of claim 16, wherein causing theenvelope of the balloon to be unpacked comprises unpacking the envelopewith a lift winch.
 18. The non-transitory computer readable medium ofclaim 17, wherein causing the envelope to be filled with the lift gascomprises filling the envelope with a fill hose coupled to the liftwinch.
 19. The non-transitory computer readable medium of claim 18,wherein the shell structure comprises an opening and wherein the fillhose and the lift winch are configured to move through the opening. 20.The non-transitory computer readable medium of claim 16, wherein thelift gas comprises a lighter-than-air gas.